Table 2.

Classification of tumor, node and metastasis of lung cancers.

T:Tumor	Tumor Characteristics
T0	Absence of primary tumor
Tis	Carcinoma in situ
T1	Tumor ≤ 3 cm in greatest diameter
T1a	Tumor ≤ 2 cm in greatest diameter
T1b	Tumor ≥ 2 cm but ≤ 3 cm in greatest diameter
T2	Tumor ≥ 3 cm but ≤ 7 cm in greatest diameter
T2a	Tumor ≥ 3 cm but ≤ 5 cm in greatest diameter
T2b	Tumor ≥ 5 cm but ≤ 7 cm in greatest diameter
T3	Tumor >7 cm Tumor invading chest wall, diaphragm, phrenic nerve, mediastinal pleura, pericardium Tumor in the main bronchus Separate tumor nodules in in the same lobe
T4	Tumor of any size invading heart, great vessels, mediastinum, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina
N:Nodes
N0	Absence of regional lymph node metastasis
N1	Metastasis in ipsilateral hilar and/or peribronchial lymph nodes and intra-Pulmonary lymph nodes
N2	Metastasis in ipsilateral mediastinal and/or subcarinal lymph nodes
N3	Metastasis in contralateral hilar or mediastinal lymph nodes, in ipsilateral or contralateral scalene lymph nodes, or in supraclavicular lymph nodes.
M:Metastases
M0	Absence of distant metastasis
M1	Distant metastasis
M1a	One or more separate tumor nodules in contralateral lobe Tumor with pleural nodules or tumor pleural/pericardial effusion
M1b	Distant metastasis